Larry Grayam

One of the common questions posted to various photography newsgroups is, I have some money and want to purchase a lens for my SLR which one should I get. The first response is often, well what kind of photography do you do? So after looking at what kind of photography we want to do we will take a look at lenses, macro, zoom, fixed focal length, wide angle and telephoto.

Are you a wildlife or sports photographer? Long glass rules these fields of photography. Shooting portraiture and glamour is often done with a short telephoto. Building interior and exterior shots may require a wide angle lens. So think about your photographic interests, search out similar thinking photographers and see what equipment they use.

Many cameras come equipped with a normal lens, with 35mm film this was typically a 50 mm lens. A normal lens would give a magnification ratio (1X), angle of view and perspective close to what the human eye would visualize. On today’s digital single lens reflex (DSLR) cameras, with a built in magnification of 1.3-1.5X, a 35mm lens would be considered normal after its 1.5X magnification.

So a wide angle lens for DSLR use would be anything shorter than 35mm. As the lens focal length decreases, the angle of view increases allowing you to include more of the scene in your photo. The close focusing point usually decreases allowing you to move closer to the subject and your depth of field (DOF) increases. The perspective also changes with wide angle lenses giving a greater sensation of depth to photographs or apparently opening up the distance between objects. The magnification ratio decreases along with the focal length. Wide angle lenses also tend to highlight imperfections or distortions, particularly around the outer edges of the frame.

Many photographers feel a wide angle is for use when you have a wide field of view to capture, while others enjoy the unique perspective and DOF possibilities offer by wide angle. And still others enjoy working in close to the subject. Many people believe that the perspective alone can change a ho-hum photo into a dazzling example of your fine photographic talent.

Telephoto lenses will magnify the image; reduce the angle of view and DOF giving a unique perspective. This affect may also be realized by the addition of a tele-converter between the camera and lens. The decreased DOF of a telephoto allows a photographer to focus tightly on a subject allowing the background to remain out of focus; this gives an extra pop to the photo.

Telephoto lenses are the first choice when you need to reach out to capture an image. The greater magnification ratios 2X-12X allow you to fill the frame at a greater distance. Yet still others are stitching together telephoto shots for unique landscape photography. Fashion and other photographers often use telephotos purely for the affect. Many photographers will use a 2-3X magnification telephoto for portraiture.

Fisheye and semi-fisheye lens are special use lenses that give an extreme wide angle view of a subject along with a very distinctive change in the perspective as well. They are considered non-rectilinear lenses in that straight lines in the photos will appear curved.

Macro or Micro lenses allow for extreme close focusing of a subject resulting in a near 1:1 magnification or reproduction on the film of digital device. Some lenses are macro all the time while others need to be configured into a close focusing mode.

Fixed focal length lenses are designed to work optimally at a precise fixed focal length. Wide angle lenses might include 14mm, 18mm, 20mm and 24mm for wide angle lenses. Telephoto might start at 85mm, 100mm, 135mm, 180mm and 200mm. Super telephotos could be 300mm, 400mm, 500mm or even 600mm lenses.

Zoom lenses are designed to work acceptably over a range of focal lengths, they can be described as wide angle, normal, or telephoto zoon lenses. An added feature of a zoom lens is the ability to zoom during a time exposure for special effect.

Manufactures have developed systems to reduce vibration or stabilize the image allowing the photographers to shoot at slower than normal shutter speeds and still create a sharp image. IS image stabilization and VR for vibration reduction are just two of the common names for these systems.

So start saving those aluminum cans and soon you will be at the camera store and then happy shooting with that new lens.-Larry Grayam